The present invention relates to a system for ventilating an internal-combustion engine crankcase as well as to such an internal-combustion engine, particularly having a V-shaped arrangement of the cylinders.
DE 101 54 669 A1 discloses an internal-combustion engine with at least two cylinder bank rows, in which oil separation chambers are provided on the interior side of the cylinder head covers for the crankcase ventilation. The oil separation chambers are an integral component of the crankcase ventilation system.
An object of the present invention is to provide a still further improved crankcase ventilation system and the connected separation of oil from the blow-by gases in order to finally be able to return purified blow-by gases to the suction system of the internal-combustion engine.
This and other objects have been achieved by providing at least one separate oil separation module whose oil separation chambers constructed therein have first openings for the introduction of the blow-by gases and second openings for the return of the separated oil into the cylinder head and a V-shaped internal combustion engine on which the oil separation module is arranged between a cylinder head cover of a cylinder bank row and the air intake module.
As a result of the fact that now a separate component is provided for the oil separation from the blow-by gases, the functionality of the crankcase ventilation can be further improved. The oil separation chamber integrated in the component module can be constructed to have a larger volume. As a result, a longer ventilation path can be implemented for the blow-by gases, so that the efficiency of the oil separation is further improved.
The transfer of the blow-by gases from the cylinder head into the oil separation chamber takes place via openings which, relative to the longitudinal dimension of the oil separation chamber, are arranged essentially in the center, while second openings for the return of the separated lubricating oil into the cylinder head are provided at the two respective ends of the oil separation chamber. In an internal-combustion engine in which the longitudinal dimension of the oil separation chamber coincides with the vehicle longitudinal axis, it is thereby ensured that, also when the motor vehicle is driving uphill and downhill, despite the lubricating oil situated in the camshaft space, the crankcase ventilation, by way of the oil separation chamber, is not impaired and separated oil can be returned via the second openings.
Because the volume fraction of the blow-by gases entering into the oil separation chamber is greater than the fraction of the separated lubricating oil, the opening cross-section for the transfer of the blow-by gases into the oil separation chamber is larger than the opening cross-section for the separated lubricating oil.
So that the blow-by gases are forced to enter the oil separation chamber via the central opening provided in the oil separation chamber, the return flow openings provided for the lubricating oil are monitored in a simple manner by valves. These valves open up a connection to the cylinder head or the camshaft space only when lubricating oil has collected in this area. The valve, which, for example, has a mushroom shape, as a result of gravitational force, then opens up the opening and thus the return flow to the camshaft space.
For the targeted guidance of the blow-by gases in the oil separation chamber, partitioning webs are provided to guide the blow-by gas in a labyrinth-type manner from the intake to the exhaust. This labyrinth-type guidance of the blow-by gases allows the space in the oil separation chamber to optimally utilized. The lengthening of the path for the blow-by gases from the intake to the exhaust connected therewith results in a further calming of the blow-by gases and thus to a better separation of the lubricating oil.
The component module for the oil separation has a trough-shaped basic body which is closed by a separate lid.
A space-saving arrangement for such an oil separation module, which is suitable for a multi-row internal-combustion engine with a V-shaped arrangement of the cylinders, is obtained when one component module respectively is arranged in each case between a cylinder head cover of an internal-combustion engine and an air intake module placed centrally in the interior of the two cylinder bank rows.
The two oil separation chambers integrated in the oil separation modules are mutually connected by means of a hose assembly.
On one of the two oil separation modules, a pressure regulator is fastened whose output leads by way of a connection line to the suction pipe of the internal-combustion engine. As a result, the vacuum existing in the suction pipe as a function of the load condition of the internal-combustion engine can be regulated to a constant vacuum value suitable for the crankcase ventilation.
An additional oil separator is connected in front of the pressure regulator. The oil separator, as viewed in the flow direction of the blow-by gases, connects to the oil separation chamber integrated in the second oil separation module and is combined with the pressure regulator to form a constructional unit.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.